Thin joint blocks are manufactured in all of the standard aircrete block strengths 2.80 N/mm2 Solar, 3.60 N/mm2 Standard and 7.30 N/mm2 Hi Seven, together with a few 10.30 N/mm2 Hi Tens. The principal difference is the accuracy and format of blocks. We tend to specify the Jumbo Plus format, which is 610mm x 270mm and manufactured to high degree of accuracy +/- 1mm.